r - R 相当于绘制地图的“等待”

Question

我想为美国的不同州添加不同的颜色。但是，当我map("state",."insert coloring condition"...)按顺序运行所有命令时，我没有得到叠加图，它只是更新地图但不保持着色（如预期的那样）。绘制图时，您可以访问lines()，points()但它不适用于地图.. 那么我该怎么做呢？

Answer 1

If you read the documentation for ?map you'll see that there is an add argument:

logical flag that specifies whether to add to the current plot. 
If FALSE, a new plot is begun, and a new coordinate system is set up.

that should do what you describe.